“If everything is left to leaders to resolve at the last minute, we risk having a weak deal or no deal at all," he said.

He spoke in New York shortly before boarding a plane for Copenhagen, where he is due to join the summit today.

The disagreements come from the increasingly polarized positions of developed and developing countries at the conference.

At times, the divisions appear eerily reminiscent of the Cold War, with Russia and China championing the developing world's demands that the world's richest countries shoulder the heaviest burden for reducing emissions.

'Differentiated Approach'

Russian President Dmitry Medvedev put this message about the summit on his official website on December 13:

"I also think that we need to use a differentiated approach in determining the commitments of developed and developing countries. We are all in different situations," he said.

"These commitments must not conflict with economic opportunities or, most importantly, the development priorities of each country. It's obvious that the young industrialized economies will be a greater drain on energy resources than the postindustrial powers that have already developed their economies."

How are we going to look...if there are more than 100 heads of state and government from all over the world, and...it was not possible to come to an agreement?

Medvedev's remarks come as China has taken the lead as the developing world's voice since the summit began on December 7.

Chinese Foreign Ministry spokeswoman Jiang Yu said today that developed countries have “put forward a plethora" of demands on developing countries and that this “will hamper the Copenhagen conference."

The political lineup at the conference is surprising because Russia, and increasingly China, are considered part of the same bloc of heavily industrialized, developed countries that they are criticizing.

That has led to mounting distrust at the conference that countries are using politics as a lever to impose their own conditions on how they will reduce their future industrial emissions.

No Outside Monitoring

China, which says it will pay for its own programs to shift to more energy-efficient technologies, is refusing to accept any outside monitoring of those efforts.

That kind of demand echoes similar calls from developing countries for special treatment or large-scale financial transfers from richer countries to help them switch to greener technologies.

Developing nations underlined their solidarity by staging a five-hour walkout of the Copenhagen conference on December 13.

The walkout was led by African countries, which say they want the world's current accord on fighting global warming – the 1997 Kyoto Protocol – to be changed to a two-track system after it expires in 2012. The two-track approach would allow for a special deal for poor states, which count on industrialization for economic progress.

The details of any special track have yet to be defined. But the approach runs counter to the desire of most rich nations, which want a single accord obliging all nations to fight global warming.

The walkout ended with conference organizers agreeing to form pairs of ministers from rich and poor nations to immediately try to bridge differences.

Ghana and Britain, for example, will examine ways to raise billions of dollars in new funds to help poor countries.

Specter Of Failure

All this suggests that a climate change agreement may be no easier to reach in Copenhagen than it was when the process kicked off with the Kyoto Protocol 12 years ago. The Kyoto accord was never ratified by the world's two biggest gas emitters – China and the United States – over their concerns it would disproportionately slow their own economic growth.

With the Copenhagen summit now in its final week, world leaders will soon begin arriving to join it before it ends on December 18.

Earlier, there was much optimism that the leaders could arrive to work out the final details needed to issue a strong closing statement committing the world to new action against global warming.

One sign of that earlier optimistic mood was U.S. President Barack Obama's decision to postpone an earlier planned visit close to the summit's opening last week in order to attend later this week instead.

Now, with the conference in deep trouble, time is running out for an agreement to still take shape at all.

"How are we going to look Friday or Saturday if there are more than 100 heads of state and government from all over the world, and what we say to the world is that it was not possible to come to an agreement?" EU Commission Chief Jose Manuel Barroso asked on December 13.